{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{6}{c}}
\toprule
                    &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}&\multicolumn{1}{c}{(4)}&\multicolumn{1}{c}{(5)}&\multicolumn{1}{c}{(6)}\\
                    &\multicolumn{1}{c}{OLS\_ALL}&\multicolumn{1}{c}{OLS\_BIG}&\multicolumn{1}{c}{BTW\_ALL}&\multicolumn{1}{c}{BTW\_BIG}&\multicolumn{1}{c}{POLS\_ALL}&\multicolumn{1}{c}{POLS\_BIG}\\
\midrule
Income              &       0.517         &       0.144         &       0.483\sym{**} &       0.120         &       0.482\sym{**} &       0.115         \\
                    &     (0.289)         &    (0.0940)         &     (0.166)         &    (0.0925)         &     (0.169)         &    (0.0901)         \\
\addlinespace
Constant            &      -21.63         &      -3.142         &      -15.64\sym{*}  &      -1.827         &      -20.49\sym{*}  &      -2.271         \\
                    &     (14.25)         &     (2.677)         &     (6.879)         &     (2.666)         &     (10.06)         &     (2.760)         \\
\addlinespace
Time effects        &          No         &          No         &          No         &          No         &         Yes         &         Yes         \\
\midrule
N                   &          43         &          26         &         645         &         390         &         645         &         390         \\
R2                  &       0.049         &       0.093         &       0.103         &       0.077         &       0.065         &       0.071         \\
\bottomrule
\end{tabular}
}
